Complete Series of 1,2‐Bis(trihalogenosilyl)benzenes (F, Cl, Br, I): A Platform for Cooperating Lewis‐Acidic Sites in Close Quarters

1,2‐Bis(trihalogenosilyl)benzenes are versatile synthetic building blocks and represent a unique class of ditopic Lewis acids. Building on the recently reported compound 1,2‐(Cl 3 Si) 2 C 6 H 2 Me 2 ( 1 Cl ; Me groups in 4,5‐positions), the practical synthetic access to its sixfold fluorinated ( 1 F ), brominated ( 1 Br ), and iodinated ( 1 I ) congeners is disclosed. Compound 1 F is obtained via Cl/F exchange on 1 Cl using SbF 3 (71%). The synthesis of 1 Br involves a [4 + 2]‐cycloaddition reaction between Br 3 SiC≡CSiBr 3 and 2,3‐dimethyl‐1,3‐butadiene to furnish the corresponding 1,4‐cyclohexadiene, which is subsequently dehydrogenated and aromatized using 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (overall 59%). Compound 1 I is formed through H/I exchange on 1,2‐(H 3 Si) 2 ‐C 6 H 2 Me 2 with BI 3 (32%). All species 1 F − 1 I are comprehensively characterized by NMR spectroscopy, X‐ray crystallography, elemental analysis, and high‐resolution mass spectrometry. Moreover, adducts of 1 F with either 1 equiv. or 2 equiv. of F − are shown to form an inverse chelate featuring a Si−( μ ‐F)−Si′ bridge or a mixed bridging/terminal coordination motif, respectively.